Atomizable mobile fuel product



Patented Sept. 11, 1928,-

ouirso s'm res; PATENT ARTHUR w. BU'RWELL; or nine-ARA FALLS, NEW YORK,ssrenoa TOALOX CHEMI- can conrona'rron, or new 201m, n. :Y.,'-AoonPonA'rIon or NEW YORK.

n'roivirzlinnn HMOBJQILE FUEL rnon oo'r.

Ho Drawing;

i This invention relates to an atomizable mobile fuel product of thetype consistmg essentially of finely divided SOllCl fuel dis-' persed ina normally liquidrfuel and held in a state of substantially stablesuspension therein by means of a stablizing agent, and

to an economical process of making the same.

tion having a higher fuel value per unit volume than fuel oil alonepreviously have I led to attempts to utilize powdered solid fuel mixedwith, or dispersed in, liquid fuel. It wasearly found that finelydivided solid fuel (e.- g.', powdered coal) settles out of an intimateadmixture of the same :with fuel economical mechanical agitation means.'25

Previous investigators have attempted to 7 stabilize the suspension offinely divided solid fuel in liquid fuel by the admixture therewith ofrosin compounds, lime-rosin grease, coal distillates, gelatin, albumen,soaps and the like. Relatively stable suspensions have been prepared bythe use of one or more ofthese stabilizing agents in the powdered solidfuel-fuel oil mixtures, articularly in those cases where the solid uelparticles have been reduced to a substantially colloidal size in thepresence of the liquid fuel and of the stabilizing agent. Such fluidfuel compositions, while exhibit? ing remarkable colloid-like propertieswith regard to the stability of the suspensions, are not of commercialuse because of the high costs entailed in their preparation.

An object of the invention is to provide an atomizable mobile fuelproduct having the said desirable characteristics, and which may beprepared in such an economical manner that the product may competecommercially with powdered coal. r

The invention is based-upon my discovery of the fact that a petroleumsoluble, nonaqueous mobile colloidal gel may be produced from a normallyliquid petroleum hydrocarbon mixture such as the petroleum distillatescommonly used as'fuel-and' known generally as fuel oils, by dissolvingthere- I a suspension. The many obviousiadvantages to be derived fromthe use of a mobile-fuel compos1-" App1ication filed lllarch 2, 1927.Serial ,No. 172,214.

in an alkali metal salt of a saponifiable, organic acidic productobtained by the controlled oxidation of a normally liquid aliphatichydrocarbon, and that finely divided solidffuel, when dispersed in saidetroleum soluble, non-aqueous mobile colloi a1 gel, is held therein in astate of substantially stable It has beenfound that by the practicing ofmy inventionthe solid .fuel (e. g., coal) need not be reduced inparticlesize to the.

colloid-like state iii-order to effect the production of a stable mobilefuel product therefrom, it. being necessary only that the solid fuelparticles be of asuliicient degree- -of fineness so that they readilymay pass thr'oughthe passages of the fuel burning apparatus withoutdanger of clogging,i. e., of about the particle size of ab ut from 100to 200 mesh. The petroleum soluble, non-aqueous, mobile, colloidal gelserving as the suspension agent for the finely divided solid fuel isprepared, as hereinbefore mentioned, by dissolving in a normally liquidpetroleum hy drocarbon mixture (e. g, fuel oil) an alkali metal salt ofa saponifiable, organic acidic product obtained by the controlledoxidation of a normally liquid aliphatic hydrocarbon or hydrocarbonmixture. The said alkali metal salt does not form with the fuel oil atrue's'olution, but forms a mobile colloidal solution, or gel whiohissufficiently fluid to permit being pumped easily- J There follows adetailed description of the preferred process of making'the petrolcmnsoluble, non-aqueous mobile colloidal gel, it being understood that theinvention is not limited to the specific materials. proportions andconditions" hereinafter to. be set out, which are understood to beexemplary:

Although the organic acidic products obtained by the controlledliquid-phase oxidation of hydrocarbons or mixtures thereof generally,under such conditions as to obtain water-insoluble, saponifiable,organic acidic. products, are adapted foruse in the preparation ofthe-aforesaid alkali metal salts, I prefer, forpurely economicalreasons, to employ the organic acidic products from the cheapest fueloil available,-for instance, the fuel oil known as"36 to 40? .Baumfueldistillate. When a:' petroleum 1,684,125 ,QFFHQE,

" carbon mixture.

- ganic compounds, unoxidized petroleum hydrocarbons, and awater-insoluble, saponifiable, organic, acidic product which is whollyor partly soluble in the petroleum hydro- In the oxidation step, the

oxidation per se may be initiated by the presence in the petroleumdistillate of a. of an oxidizing catalyst, such small amount as acompound of manganese, copper or iron,

say manganese stearate, amounting toabout 0.1 ercent of the weight ofthe petroleum distillate. Or, the oxidation may with equal facility beinitiated by providing as the charge of raw material to undergooxidation a mixture comprising about equal parts by weight or volume offresh petroleum distillate and unoxidized petroleum hydrocarbons from apreviously treated charge.

The oxidation step preferably is terminated at a point where incipientformation of oxidation products insoluble in the 'reaction mixturecommences; e. g. at a point where the partially oxidized mass containsfrom about 'to'about percent of saponifiable acidic roducts as titratedfor a molecular weig t of 280. acidic products consist essentially ofsimple aliphatic carboxylic acids derived from the aliphatichydrocarbons which made up the bulk'of the petroleum distillate startingmaterial. They are insoluble in water but soluble in the petroleumdistillate.

For obtaining the desired saponifiable organic acid product, theabove-described reaction mixture is washed withwater, thereby removingthe water-soluble" acids, and the resulting washed product is treatedwith an aqueous solution of a caustic alkali in quantity sufiicient to'saponify the acid compounds constituting the said water-insoluble,saponifiable organic acidic product. The reaction mixture resulting fromthe treatment with caustic alkali solution is diluted with water,-inorder to throw out of solution any dissolved unsaponified material,whereby there are formed, upon standing. a supernatant non-aqueousoilylayer comprising'unoxidized material and unsaponifiable products ofoxidation, and a subnatant aque ous layer comprising a solution of thealkali metal salt of the saponifiable organic acidic product. v

The subnatant aqueous layer is carefully separated from the supernatantoily layer of about from These saponifiable i,ea4,iab

and is dehydrated to a The dehydration may danger of charring, bysubjecting the aqueperfectly dry mass.

ous solution to evaporation treatlnent at'a.

than from the soap solution alone; also, the

soap solution is less prone to decomposition. To the solution ofnon-aqueous soap in fue a; 'sufiicient quantity of fuel oil to yield thedesired concentration .of soap in the mixture.

The dehydrated mass, resulting from the above described treatment andconsisting esscntially of the alkali metal salt of the saponifiableorganic acidic product obtained by the controlled oxidation of anormally liquid petroleum hydrocarbon mixture, is found to be soluble inordinary fuel oil to the production of a colloidal solution. Saidcolloidal solution-has strong gel-forming tendencies, it being a factthat the presence of only about 1 to 2 parts by weight of said alkalimetal salt in parts by weight of the solution effects the production ofa colloidal gel which, while sufiiciently fluid to be pumped easily, iscapable of holding therein powdered coal having a particle size 100 to200 mesh in astate of stable suspension for a prolonged period of time,i. e., a month or more. The onversion of the fuel oil from a liquidstate to the state of a mobile gel apparently does not detract from itsfuel value. 'Powdered coal of about from 100'to 200 mesh is introducedinto said fuel "oil gel and suspended therein by simple mechanicalagitation.

The relative proportion of powdered coal to fuel oil gel may be variedwithin wide limits, it being possible to prepare a stable mobile fuelproduct therefrom containing equal parts by weight of the coal and thegel. It is to be noted that the relative proportions of the coal and thegel may be so selected as to obtain an atomizable mobile fuel producthaving a predetermined thermal value and density per unit of volume. Forexample, the powdered coal-and the fuel oil gel may be brought togetherin" such proportions as to yield a weight between 8 and 12 pounds pergallon (231 cubic inches) of space and having, especially in the moredense compositions, a thermal value much greater thanthat of an equalvolume of fuel oil or of powdered coal alone. It is a remarkable factthat, although on long standing there may occur some stratibe effected,without.

product ranging in an oil obtained by the above procedure, I add" 1.Process which comprises producing apetroleum soluble, non-aqueous mobilecolloidal gel from amormally liquid petroleum hydrocarbon mixture andsuspending in said non-aqueous mobile colloidal gel finely divided solidfuel.

an atomizable 2. Process of producin ving the suspenmobile fuel productinvo sion of finely divided solid fuel in a liquid fuel in the resenceof a stabilizing agent, characterized in that there is used as thestabilizing agent a petroleum soluble, alkali metal ,salt of asaponifiable organic acidic product substantially identical with that obtained by contacting an oxidizing gas with a normally liquid petroleumhydrocarbon mixture, in liquid phase, at reacting temperatures and at apressure greater than atmospheric pressure.

3. Process of producing an atomizable mobile fuel product whichcomprises dissolving in a normally liquid petroleum hydrocarbon mixturea petroleum soluble, neutral alkali metal salt of a saponifiable organicacidic product substantially identical with that obtained by contactingan oxidizing gas with a normally liquid petroleum hydrocarbon mixture,in liquid phase, at reacting temperature and at a pressure greater thanatmospheric, whereby there is obtained a mobile colloidal gel of saidnormally liquid petroleum hydrocarbon mixture, and suspending in saidmobile colloidal gel finely dividedsolid fuel.

4. As a new atomizable mobile fuel product, a substantially stablesuspension of finely divided solid fuel in a non-aqueous, mobile,colloidal'gel comprising a normally liquid petroleum hydrocarbon mixtureand a petroleum soluble alkali metal salt of a saponifiable organicacidic roduct substan tially 'dent'cal with that o tained by contactmgan oxidizmg gas with a normally etroleum hydrocarbon mixture, in

liquid iase, at reacting temperature and at liquid p a pressure greaterthan atmospheric pressure.

5. As a new atomizable mobile fuel prodnot, a substantiall stablesuspension of finely divided soli fuel in a non-aqueous mobile,colloidal gel comprising a solution containing about 98 parts b weightof a normally li uid petroleum hy rocarbon mixture and a ut 2 parts byweight of a petroleum soluble alkali metal salt of a saponifiableorganic acidic roduct substantially identical with that o tained bycontac'ting an oxidizing gas with a normallyliquid petroleum hydrocarbonmixture, in liquid phase, at reacting temperature and at a pressuregreater than atmospheric pressure.

6. As a new atomizable mobile fuel product, a composition comprisingabout 100 parts by weight of powdered coal having a particle size ofabout from 100 to 200 mesh suspended ina fuel oil gel consisting ofabout 98 parts by weight of a normally liquid fuel oil and about 2 partsby weight of a petroleum soluble alkali metal salt of a saponifiableorganic acidic product substantially identical with that obtained bycontacting an oxidizing gas with a normally liquid petroleum hydrocarbonmixture, in liquid phase, at reacting temperature and at a pressuregreater'than atmospheric pressure. i

7. Process of producing an atomizable mobile fuel solving in a normallyliquid petroleum h drocarbon mixture an alkali metal saltof asaponifiableorganic acidic product obtained by the controlled oxidationof normally liquid petroleum hydrocarbons.

8; As a new atomizable mobile fuel product, a substantially stablesuspension of finely divided solid fuel in a: non-aqueous, mobile,containing. a normally liquid petroleum hydrocarbon mixture and analkali metal product which comprises discolloidal gel, comprising asolution obtained by the controlled oxidation of a normally liquidpetroleum hydrocarbon mixture.

' In testimony whereof, I afiix my signature ARTHUR W. BURWELL.

